1. Field of the Invention
The present invention pertains to the maintenance and repair of power generating machines; preferably, but not exclusively, turbine engines. More specifically, the present invention relates to the preparation of the large threaded bolts that must be carefully inspected as to avoid gauld threads in the reassembling of these large industrial machines. During their lifetime the bolt threads are dented and damaged. Without isolating and repairing upset bolt threads, before replacing their corresponding nuts, the nuts can become stuck and/or the costly bolt destroyed.
2. Related Art
Until now the inspection of such bolts has been a slow and time consuming process requiring simple visual examination. When a particular thread is judged unacceptable by the examiner, a metal file is used to work the suspected damage out of the bolt thread. One aspect of particular difficulty with this method is that many times the damaged thread is not obvious to the unaided eye. Mistakes or errors in visual inspections cause considerable loss of productivity, as nuts must then be repeatedly removed due to unforeseen thread damage, as well as unnecessary efforts expended filing workable threads.
In order to provide background information of related art so that the invention may be appreciated and understood in its own context reference may be made to the following U.S. patents:
U.S. Pat. Nos. 5,309,490 (Bayerstern): 5,157,802 (Guidry et al.): 4,403,363 (Hess): and 4,014,062 (Scott et al.)
Note: all which pertain to using brushes for threaded bolt cleaning.
No device is known to aid exclusively in the detection of upset and damaged threads of large industrial bolts as this invention advances the art.